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Wisconsin CDL Practice Test: Air Brakes - Test 2019

(From the 2019 Wisconsin CDL Handbook)
Number of tests: 1
Number of questions: 25
Passing score: 80

Directions: To obtain this endorsement required to drive a vehicle with air brakes, applicants must pass a 20-question test. And to pass the test, applicants must score at least 80%. Test questions are from the Wisconsin Commercial Driver Handbook. The School Bus endorsement can be used with the Class A, B, or C CDL. If you need additional information, please contact your local DMV office. You can find your nearest DMV office at Wisconsin DMV locations.

You have made 2 errors so far.
1. What part of the truck is the air compressor connected to?
  • Radiator

  • Engine

  • Transmission

2. When going down a steep downgrade,
  • The air brakes should be used

  • The vehicle should be continually downshifted instead of using the brakes

  • The vehicle should be placed in a lower gear and brakes used to supplement braking

3. If the vehicle has air brakes, the air compressor drive belt should be checked before each drive. In what condition should the belt be in?
  • Tight

  • Cracked

  • Loose

4. What kind of force must emergency brakes use?
  • Mechanical

  • Heavy

  • Air pressure

5. A dual air brake system:
  • Has a single air brake system, but have two sets of controls

  • Has two separate air brake systems which use a single set of controls

  • Has one air brake system for the left side and right side of the truck

6. Having ABS on only one axle:
  • Will slow the vehicle, but not stop it

  • Can be dangerous

  • Should still give you more control